Light on the sustainable preparation of aryl-cored dibromides

• Fabrizio Roncaglia,
• Alberto Ughetti,
• Nicola Porcelli,
• Biagio Anderlini,
• Andrea Severini and
• Luca Rigamonti

Beilstein J. Org. Chem. 2024, 20, 1076–1087, doi:10.3762/bjoc.20.95

• molecular wires or extended structures – either linear or cyclic – with enhanced functionality. Consequently, they play a crucial role in the fabrication of polymers [4][5][6][7], cyclophanes [8], photoactive materials [9][10][11], membranes [12], and other architectures. The synthetic potential of aryl

AlBr₃-Promoted stereoselective anti-hydroarylation of the acetylene bond in 3-arylpropynenitriles by electron-rich arenes: synthesis of 3,3-diarylpropenenitriles

• Yelizaveta Gorbunova,
• Dmitry S. Ryabukhin and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2021, 17, 2663–2667, doi:10.3762/bjoc.17.180

• in a similar AlCl3-catalyzed hydroarylation of an acetylene bond in the synthesis of cyclophanes [26]. Additionally, the cyclization of two selected nitriles 2c,g into 3-arylindanones 3a,b correspondingly was carried out in triflic acid TfOH (CF3SO3H) at room temperature for 1 h (Scheme 3). The

Breaking paracyclophane: the unexpected formation of non-symmetric disubstituted nitro[2.2]metaparacyclophanes

• Suraj Patel,
• Tyson N. Dais,
• Paul G. Plieger and
• Gareth J. Rowlands

Beilstein J. Org. Chem. 2021, 17, 1518–1526, doi:10.3762/bjoc.17.109

• Suraj Patel Tyson N. Dais Paul G. Plieger Gareth J. Rowlands School of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand 10.3762/bjoc.17.109 Abstract Substituted [2.2]metaparacyclophanes are amongst the least studied of the simple cyclophanes. This is

• ]metaparacyclophane and a cyclohexadienone cyclophane. Keywords: cyclophane; metaparacyclophane; nitration; paracyclophane; rearrangement; Introduction Cyclophanes have been described as having bent and battered benzene rings [1] due to a structure that involves one, or more, aromatic rings linked by aliphatic

• sample. Our best conversion, judged by 1H NMR, gave 21% of 3 along with unreacted 1. The two unsubstituted isomeric cyclophanes, 1 and 3, could not be separated by standard chromatographic techniques. Next, we attempted the rearrangement of a range of 4-substituted [2.2]paracyclophanes, including 4

Selective recognition of ATP by multivalent nano-assemblies of bisimidazolium amphiphiles through “turn-on” fluorescence response

• Rakesh Biswas,
• Surya Ghosh,
• Shubhra Kanti Bhaumik and
• Supratim Banerjee

Beilstein J. Org. Chem. 2020, 16, 2728–2738, doi:10.3762/bjoc.16.223

• electrostatic and (C–H)···O− hydrogen bonds involving the acidic proton at the 2-position of the imidazolium moiety to bind to ATP and other phosphate analytes [46]. A number of cyclophanes and tweezers [53][54][55][56] have been reported possessing the following common structural features: a) the presence of

Formation of alkyne-bridged ferrocenophanes using ring-closing alkyne metathesis on 1,1’-diacetylenic ferrocenes

• Celine Bittner,
• Dirk Bockfeld and
• Matthias Tamm

Beilstein J. Org. Chem. 2019, 15, 2534–2543, doi:10.3762/bjoc.15.246

• monomeric and dimeric ring-closed products. As shown before by our group with other cyclophanes, these can also be determined theoretically to predict the synthetic outcome of a metathesis reaction [95]. To further complete the series of diacetylenic ferrocene substrates for the catalytic RCAM the analogous

Synergistic approach to polycycles through Suzuki–Miyaura cross coupling and metathesis as key steps

• Sambasivarao Kotha,
• Milind Meshram and
• Chandravathi Chakkapalli

Beilstein J. Org. Chem. 2018, 14, 2468–2481, doi:10.3762/bjoc.14.223

• with Suzuki–Miyaura cross coupling in combination with metathesis (or vice-versa). Several cyclophanes, polycycles, macrocycles, spirocycles, stilbenes, biaryls, and heterocycles have been synthesized by employing a combination of Suzuki cross-coupling and metathesis. Various popular reactions such as

• the corresponding epoxide 110. Unfortunately, generation of epoxide was not realized (Scheme 16). Macrocycles To develop new synthetic strategies to various cyclophanes, we conceived a sequential usage of the SM coupling and RCM as key steps [48][49]. In this context, the required dialdehyde 113 (80

• and RCM as key steps. Synthesis of cyclophane 120 and 122 via SM coupling and RCM as key steps. Synthesis of cyclophanes via SM and RCM. Synthesis of MK-6325 (141) via RCM and SM coupling. Acknowledgements We thank the Council of Scientific and Industrial Research (CSIR), New Delhi [02(0272)/16/EMR

Synthesis and post-functionalization of alternate-linked-meta-para-[2ⁿ.1ⁿ]thiacyclophanes

• Wout De Leger,
• Koen Adriaensen,
• Koen Robeyns,
• Luc Van Meervelt,
• Joice Thomas,
• Björn Meijers,
• Mario Smet and
• Wim Dehaen

Beilstein J. Org. Chem. 2018, 14, 2190–2197, doi:10.3762/bjoc.14.192

• ; Introduction The ability of cyclophanes to form three-dimensional cavities is interesting for various potential applications, e.g., as supramolecular hosts. Synthetic procedures towards novel cyclophanes have attracted much interest in the scientific community [1][2][3][4]. An interesting subclass of

• cyclophanes is formed by thiacyclophanes, in which the thioether linkages impose less conformational strain and which have an increased cavity size compared to other (oxa/aza)cyclophanes. Thiacalix[n]arenes are among the most widely known thiacyclophanes with significant ability for molecular recognition [5

• ], less synthetic work has been performed on the synthesis of sulfur-linked cyclophanes with an alternating meta-para-bridge [26]. Herein we report a one-pot macrocyclization of meta-para-bridged thiacyclophanes by means of a substitution reaction between the biselectrophile 2,6-bis(chloromethyl)-4-tert

Steric “attraction”: not by dispersion alone

• Ganna Gryn’ova and
• Clémence Corminboeuf

Beilstein J. Org. Chem. 2018, 14, 1482–1490, doi:10.3762/bjoc.14.125

• proteins [32], heteroaromatic cores that are the common building blocks for organic semiconductors [33], cyclophanes [34], Wilcox torsion balance systems [35], etc. The recognized importance of charge penetration in various chemical problems is paralleled by myriad developments aimed at accurately

Co-solvation effect on the binding mode of the α-mangostin/β-cyclodextrin inclusion complex

• Chompoonut Rungnim,
• Sarunya Phunpee,
• Manaschai Kunaseth,
• Supawadee Namuangruk,
• Kanin Rungsardthong,
• Thanyada Rungrotmongkol and
• Uracha Ruktanonchai

Beilstein J. Org. Chem. 2015, 11, 2306–2317, doi:10.3762/bjoc.11.251

• . [23] reviewed the hydrophobic effect of supramolecular complexes from MD simulation studies and emphasized that the non-covalent driving force of high-energy water in the cavity of cyclodextrins, cyclophanes and cucurbiturils was an essential factor for complexation with the guest molecule. MD

Beyond catalyst deactivation: cross-metathesis involving olefins containing N-heteroaromatics

• Kevin Lafaye,
• Cyril Bosset,
• Lionel Nicolas,
• Amandine Guérinot and
• Janine Cossy

Beilstein J. Org. Chem. 2015, 11, 2223–2241, doi:10.3762/bjoc.11.241

• hypothesized that the steric hindrance caused by the sulfone groups might reduce the ability of the nitrogen atom in deactivating the ruthenium catalyst. A desulfonylation followed by a hydrogenation of the double bond afforded normuscopyridine (Scheme 23). Other syntheses of cyclophanes using RCM were

[2.2]Paracyclophane derivatives containing tetrathiafulvalene moieties

• Laura G. Sarbu,
• Lucian G. Bahrin,
• Peter G. Jones,
• Lucian M. Birsa and
• Henning Hopf

Beilstein J. Org. Chem. 2015, 11, 1917–1921, doi:10.3762/bjoc.11.207

• -state architecture tends to be as stacks or layers with their long axes mutually parallel. [2.2]Paracyclophane and its derivatives has been the subject of particular interest since their discovery, more than six decades ago [3][4][5]. Most of the unique properties of these cyclophanes are the result of

Design and synthesis of hybrid cyclophanes containing thiophene and indole units via Grignard reaction, Fischer indolization and ring-closing metathesis as key steps

• Sambasivarao Kotha,
• Ajay Kumar Chinnam and
• Mukesh E. Shirbhate

Beilstein J. Org. Chem. 2015, 11, 1514–1519, doi:10.3762/bjoc.11.165

• Sambasivarao Kotha Ajay Kumar Chinnam Mukesh E. Shirbhate Department of Chemistry, Indian Institute of Technology-Bombay, Powai, Mumbai-400 076, India, Fax: 022-2572 7152 10.3762/bjoc.11.165 Abstract We demonstrate a new synthetic strategy to cyclophanes containing thiophene and indole moieties

• containing polar functional groups [1]. As part of a major program aimed at developing new and intricate strategies to cyclophanes [2][3][4][5][6][7][8][9][10], we envisioned various building blocks [11] by ring-closing metathesis (RCM) as a key step [12][13][14][15][16][17][18][19][20][21][22][23][24][25

• ]. Cyclophanes containing different heterocyclic systems are difficult to assemble [26][27][28][29][30][31]. However, we believe that architecturally complex cyclophanes can be accessed by employing a reasonable selection of a synthetic strategy [32]. To enhance the chemical space and also the diversity of

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• cyclophanes. To keep the length of the review at a manageable level the literature related to orthocyclophanes was not included. Keywords: addition reactions; coupling reactions; cyclophane; metathesis; muscopyridine; name reactions; natural products; Indroduction Cyclophanes [1][2][3][4][5][6][7][8][9][10

• (s) between the aromatic rings and also provide flexibility to the overall structure. Cyclophanes play an important role in “host–guest” chemistry [39][40][41][42][43] and supramolecular assembly [44][45][46][47]. “Phane”-containing molecules show interactions with π-systems, and they can also bind

• to a large number of cations, anions, and neutral molecules. Cyclophanes are widely used in materials science and molecular recognition processes [48][49][50][51][52]. A general classification of cyclophanes is as follows: [n]orthocyclophane, [n]metacyclophane, and [n]paracyclophane (1–3) (Figure 1

The preparation of new functionalized [2.2]paracyclophane derivatives with N-containing functional groups

• Henning Hopf,
• Swaminathan Vijay Narayanan and
• Peter G. Jones

Beilstein J. Org. Chem. 2015, 11, 437–445, doi:10.3762/bjoc.11.50

• preparation of various cyclophanes bearing substituents with nitrogen-containing functional groups, e.g., the pseudo-ortho diamine 8, the bis secondary amine 23, and the crownophanes 18 and 19. Several of these new cyclophane derivatives (18, 19, 22, 26, 28) have been characterized by X-ray structural

• analysis. Keywords: azides; crownophanes; cyclophanes; isocyanates; stereochemistry; X-ray analysis; Introduction Although hundreds of mono- und disubstituted derivatives of [2.2]paracyclophane [3][4] have been described since its initial preparation [5], relatively little is known about more highly

• compounds [30], we are now in a position to prepare the tetramines 10 and 11 as the next steps to novel polyfunctionalized cyclophanes. A selection of highly substituted/functionalized [2.2]paracyclophanes. A selection of [2.2]paracyclophanes carrying several nitrogen-containing substituents. (a, above

Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

• Henning Hopf,
• Swaminathan Vijay Narayanan and
• Peter G. Jones

Beilstein J. Org. Chem. 2014, 10, 2021–2026, doi:10.3762/bjoc.10.210

• and spectroscopic data. The sequence presented here constitutes the simplest route so far to cyclophanes carrying an annelated five-membered ring. Keywords: aldol condensation; cyclopentadienones; cyclophanes; multibridged cyclophanes; stereochemistry; X-ray analysis; Introduction We have reported

• for novel cyclophanes (Scheme 1). For example, 2 has been converted into the corresponding bis-olefin, from which multi-layered ferrocene complexes (“metallocenophanes”) were prepared [6]. Analogously, from 4 several tropyliophane salts were obtained [5]. In the case of the cyclopentenone-annelated

• compounds 2 we previously prepared precursors such as 5 (easily available by Wittig–Horner reaction of the appropriate bis-formyl cyclophanes) and subjected them to catalytic hydrogenation followed by a double Friedel–Crafts cyclization. However, it appeared to us that a more direct route to these useful

Building complex carbon skeletons with ethynyl[2.2]paracyclophanes

• Ina Dix,
• Lidija Bondarenko,
• Peter G. Jones,
• Thomas Oeser and
• Henning Hopf

Beilstein J. Org. Chem. 2014, 10, 2013–2020, doi:10.3762/bjoc.10.209

• extensive column chromatography/recrystallization. Isomer 11 is chiral and could be separated on a column impregnated with cellulose tris(3,5-dimethylphenyl)carbamate. The bridge-extended cyclophane precursor 18 furnished the ring-enlarged cyclophanes 19 and 20 on Glaser–Hay coupling. Cross-coupling of 4

• their usual spectroscopic and analytical data, the new cyclophanes 11, 12, 19, 20, 22, and 26 were characterized by X-ray structural analysis. Keywords: carbon-rich molecules; complex carbon scaffolds; cyclophanes; Glaser coupling; multibridged cyclophanes; X-ray analysis; Introduction Several years

• essentially normal geometries for the metal center and the cyclophane systems, although the latter show a twist angle of 9.8°; they are tilted by ca. 45° with respect to the aromatic ring C10–C15. There is some evidence of strain in the short bridges between the cyclophanes; thus the bond C6–C9 is at 1.499(2

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Cation affinity numbers of Lewis bases

• Christoph Lindner,
• Raman Tandon,
• Boris Maryasin,
• Evgeny Larionov and
• Hendrik Zipse

Beilstein J. Org. Chem. 2012, 8, 1406–1442, doi:10.3762/bjoc.8.163

• phosphanes of otherwise comparable substitution pattern. The combination of phosphanes with unusually strained cyclic substituents such as diamandoids or cyclophanes also appears to have no particularly unusual effects. Phosphanes with strongly electron-withdrawing substituents such as PF3 (303) have the

Use of mixed Li/K metal TMP amide (LiNK chemistry) for the synthesis of [2.2]metacyclophanes

• Marco Blangetti,
• Patricia Fleming and
• Donal F. O'Shea

Beilstein J. Org. Chem. 2011, 7, 1249–1254, doi:10.3762/bjoc.7.145

• possible explanation for this is the cumbersome methods required for their synthesis. Typical approaches have utilised Wurtz coupling, the oxidation and thermal (500–600 °C) extrusion of SO2 from dithia[3.3]cyclophanes or the photochemical ring contraction of diselena[3.3]cyclophanes [17][18][19][20][21

Intraannular photoreactions in pseudo-geminally substituted [2.2]paracyclophanes

• Henning Hopf,
• Vitaly Raev and
• Peter G. Jones

Beilstein J. Org. Chem. 2011, 7, 658–667, doi:10.3762/bjoc.7.78

• slightly shorter than the length of a p-orbital, an ideal prerequisite for an intraannular reaction to take place should other factors, such as excessive strain, not prevent it. In principle, cyclophanes such as 1 are thus excellent model compounds for “molecular workbenches” [16][17][18][19] and we have

• photoisomerization of the tetraene 11 to the cyclooctadiene-bridged cyclophanes 13 and 15 and the iosmerization of 22 to 23 and 24 remain to be established, these processes allow the introduction of a completely new type of additional bridge into [2.2]paracyclophanes. For several of these new polycyclic molecules

• . Photolysis of tetraene 11. Photolysis of trans,trans-dienal 10. Cis–trans-isomerizations of the double bonds of the pseudo-geminal cyclophanes 11 and 19. Preparation of the vinylcyclopropanes 22–24. Crystallographic data for compounds 13, 15, (Z,Z)-22, 23 and 24.

Recent advances in the development of alkyne metathesis catalysts

• Xian Wu and
• Matthias Tamm

Beilstein J. Org. Chem. 2011, 7, 82–93, doi:10.3762/bjoc.7.12

• o-, m- and p-bis(3-pentynyloxymethyl)benzenes 17 (Table 3). While the cyclic product 16 was obtained from 15 in high yield (95%), different selectivities toward the formation of monomeric [10]cyclophanes 18 and [10.10]cyclophanes 19 depending on the substitution pattern were observed [77]: The

Preparation and NMR spectra of four isomeric diformyl[2.2]paracyclophanes (cyclophanes 66)

• Ina Dix,
• Henning Hopf,
• Thota B. N. Satyanarayana and
• Ludger Ernst

Beilstein J. Org. Chem. 2010, 6, 932–937, doi:10.3762/bjoc.6.104

• , and were characterized by their spectroscopic data. The individual isomers can now be easily identified from their 1H NMR spectra even if only one of them is present. Keywords: cyclophanes; diformyl[2.2]paracyclophanes; layered compounds; NMR spectroscopy; structure assignment; Introduction

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

[3.3]Dithia-bridged cyclophanes featuring a thienothiophene ring: synthesis, structures and conformational analysis

• Sabir H. Mashraqui,
• Yogesh Sanghvikar,
• Shailesh Ghadhigaonkar,
• Sukeerthi Kumar,
• Auke Meetsma and
• Elise Trân Huu Dâu

Beilstein J. Org. Chem. 2009, 5, No. 74, doi:10.3762/bjoc.5.74

• Institut de Chimie des Substances Naturelles, C.N.R.S., 91190 Gif-sur-Yvette, France 10.3762/bjoc.5.74 Abstract The synthesis of [3.3]dithia-bridged cyclophanes 7, 9 and 11 incorporating a fused heterocycle, thieno[2,3-b]thiophene is described. The structures are established by 1H NMR analysis and, in the

• case of 11, also by single crystal X-ray crystallography. Conformational analysis by variable temperature NMR suggests that cyclophanes 7, 9 and 11 exhibit conformationally rigid bridges and rings at least up to 130 °C. Energy minimization of 11 revealed anti-11 to be the most stable conformation

• ]dithia-bridged cyclophanes; dynamic NMR analysis; thieno[2,3-b]thiophene; X-ray crystal structure; Introduction The synthesis, molecular structures and conformational dynamics of short-bridged cyclophanes continue to engage interest in supramolecular chemistry [1][2][3][4]. The study of the

Reversible intramolecular photocycloaddition of a bis(9-anthrylbutadienyl)paracyclophane – an inverse photochromic system. (Photoactive cyclophanes 5)

• Henning Hopf,
• Christian Beck,
• Jean-Pierre Desvergne,
• Henri Bouas-Laurent,
• Peter G. Jones and
• Ludger Ernst

Beilstein J. Org. Chem. 2009, 5, No. 20, doi:10.3762/bjoc.5.20

• recovered by irradiation at 306 nm or by heating. This ‘inverse’ photochromic system has a potential for optical information storage, compound 4 being stable in visible light, at ambient temperature. Keywords: anthracenes; cyclophanes; inverse photochromism; photocycloaddition; Introduction Photochromism

• carbons (54.9 to 66.0 ppm) and finally 4 to CH2 (31.6 to 36.5 ppm), attributable to the ethanocyclophane bridges. In previously studied cyclophanes, the cyclobutane rings exhibited 13C signals between 42 and 51 ppm [18][19]. No such signals are apparent in the present case; therefore it is proposed that